Karnataka, which is one of India’s most arid states, has seen a reduction in rainfall in large parts of the state under both monsoon seasons because of climate change, according to a study that analysed the rainfall pattern from 1960 to 2017.
The reduction is more significant in July — a crucial month of the southwest monsoon season, when sowing is taken up on a large scale in the state.
The study titled ‘Climate Change Scenario in Karnataka’ submitted to the government by the Karnataka State Natural Disaster Management Centre (KSNDMC) also shows that the probability of drought has increased in many parts of the state over the last four decades.
“The quantum, intensity, and distribution of rainfall have varied across the regions in the state from P1 (1960-1990) to P2 periods (1991-2017),” the report said, noting that districts such as Kodagu, Dakshina Kannada, Uttara Kannada, Kalaburagi and Yadgir recorded a reduction in the amount of rainfall, whereas Shivamogga and Hassan saw a slight increase.
According to ‘Rainfall Atlas of Karnataka’, which plotted various parameters of rainfall variation across 176 taluks between 1960-2017, 83 taluks — prominently in coastal and Malnad districts — saw a reduction in rainfall. There was a “significant reduction” in 16 taluks, almost all of which were in the coastal or Malnad region. Fifty-two taluks — a majority in South Interior Karnataka — witnessed an increasing trend.
Similar trends of reduction in rainfall were observed when the whole southwest and northeast monsoon seasons were assessed. “Reduction is prominent in regions which generally receive very good rainfall, whereas the marginal increase is in dry regions,” GS Srinivas Reddy, Director, KSNDMC, who is among the authors of the parametric assessment, told DH.
“The high spatial and temporal variability of rainfall distribution has been the cause of recurring and widespread drought in Karnataka.... The recurrence of droughts and floods because of changing rainfall patterns caused by climate change will be detrimental to the surface and groundwater recharge and also pose a great challenge to water security,” the report said.
The study also noted that the annual variability of rainfall has increased in both North and South Interior Karnataka, increasing the frequency of droughts. The duration of dry spells — the interval between rainfall during monsoon seasons — has also spiked, it noted.